A life reconstruction of the famous Spinosaurus. The original fossils of this animal were destroyed by a bombing raid in 1944.
Photograph: Holger Hollemann/EPA

Periodically palaeontologists will announce a new candidate for the largest dinosaur to have ever walked the Earth with the finding of a new specimen or species. There are multiple credible candidates for this title on display in various museums though sadly each is inevitably represented by less than complete remains. Most recently a new giant from Argentina has been on show in the US that might top the lot, but even this may not have beaten a near mythical animal:a giant that was known from a single and incomplete top part of a vertebra from the middle of the spine.

‘Was’ is critical here because the specimen is no longer in existence. It was extremely fragile and at some point shortly after its discovery it apparently crumbled and fell apart. Such a fate is not uncommon for some kinds of fossils where exposure to the air or being freed from the supporting matrix can lead to specimens disintegrating but this was before the development of glues that could help consolidate and preserve fragile specimens, and it is also likely that no one immediately realised this was a risk.

Discovered in 1877 and then named the following year by palaeontologist Edward Cope, this small fragment of a dinosaur was still enough to establish that it was a new genus and a truly giant animal. It would have been a close relative of Diplodocus and so would have been relatively long and slender but the various estimates put on its size run from the outrageous to the almost inconceivable. There are, of course, plenty of issues with scaling up from incomplete remains and the general problems of correctly estimating dinosaur sizes but even the lower estimates that have been put forwards based on Cope’s description come in at 40m in length.

A near complete skeleton of Diplodocus, a close relative of Amphicoelias. The latter would have been perhaps at least twice as long as this huge 25m animal.
Photograph: Alamy Stock Photo

This is, however, the problem – we are not working from the fossil anymore but the description of it alone. Palaeontology has enough issues with incomplete and fragmentary specimens without those we do have going missing. It’s fundamentally impossible to verify Cope’s measurements and his interpretation of the data because that data no longer exists. It’s been suggested that the specimen was either incorrectly measured or recorded and the resultant colossal figures for this animal are ultimately the result of scaling from an original that was listed as being bigger than it was, even if that was accidental. Sadly, until any comparably large remains are found (and even if they exist, we may never get them) this animal will remain all but apocryphal.

This is not the only famous lost dinosaur though – Jurassic Park brought Spinosaurus to the attention of the public but this unusual predatory dinosaur was named in 1915 and had long been the subject or great debate as it was so unusual. Part of this stemmed from the limited information available on it as the original specimens (a jaw and some vertebrae and other bits) on display in Munich were destroyed by an allied bombing raid in April of 1944. All that remains again are the original descriptions and then some photos that later came to light.

Again, this leaves some frustrating gaps in our knowledge – there are suggestions that the original fossils may have actually been more than one different species that were mixed up together. Without the specimens to hand that is hard to say either way. At least in the case of Spinosaurus we have now found various new specimens but working out the taxonomy of this genus is complicated by the fact that the original material on which the name was based no longer exists. There are suggestions that there are multiple spinosaurs living at this time and working out which may be which is inevitably complicated by the absence of this critical material.

Plenty of other famous fossil specimens have also been lost. Other dinosaurs were also lost during the World Wars including some of the original bones of Thecodontosaurus, a small dinosaur from Bristol. While many survived, important fossils were lost though axis bombing of Bristol in 1940. Various Canadian dinosaur specimens en route to the UK were lost when the ship they were on was sunk by the German Navy. And it’s not just dinosaurs, the famous hominid fossils of the original “Peking Man” went missing from a train in the fog of war of 1941.

There remains hope that some of these may have actually survived somewhere, manifests for ships and train changed all the time and were not always recorded. Given how many important art and fossil treasures turn up decades after they have been thought lost or destroyed it’s not impossible that some great lost treasures will yet return. Museums are of course supposed to protect the specimens in their care and sadly things do go missing or are stolen and accidents happen, though it’s hard to hand out any blame for falling bombs or self-destruction of fragile fossils. Happily these days museum are more aware of problems like the latter and there’s good reason to think that dinosaurs being put into care now will still be available for study centuries in the future, bombing raids permitting.